The present invention relates to water purification and filtration systems and, in particular, to a disposable cartridge system having a manifold which cooperates with the cartridge to interrupt the supply and return lines during cartridge changes to prevent drainage from the supply system.
A particular problem experienced with the changing of single appliance water purification/filtration cartridges is the necessity of dealing with drainage released from the supply and return lines with the release of the cartridge from a system manifold. Unless shutoff valves are provided in the system supply lines that mate to the manifold, water typically drains from one or both of the conduits with the removal of the cartridge from the manifold. The sporadic frequency of the cartridge changes and attendant operator forgetfulness to the problem typically results in drainage. That is, the maintenance personnel forget to mount a catch pan or other spill prevention appliance beneath the manifold and it becomes necessary to clean up the spill.
A number of cartridge systems which are subject to the foregoing problem are disclosed at U.S. Pat. Nos. 3,746,171; 4,515,692; 4,915,831; 4,877,521; and 5,354,464. The cartridges of the disclosed systems variously provide projecting bayonet return ports which mate with recessed outflow cavities at the manifold. Twist lock mountings to the manifold are also provided at some of the cartridges. Cartridge interlock retainers are also disclosed. However, flow control valving is not provided at either the manifold or cartridge for any of the foregoing systems. Nor do any of the cartridges include surfaces which cooperate with associated valving.
In appreciation of the foregoing problem and inconvenience, the present manifold and cartridge system was developed. In contrast to conventional cartridges, the manifold of the invention provides a bayonet fitting at a center out flow port which couples to a recess at the cartridge. Seals displaced along the fitting and internal to the cartridge contain viral contaminants to the cartridge. A spring biased stem valve at the manifold inlet port cooperates with a raised, tapered surface at the cartridge to permit flow only upon the rotational seating and locking of the cartridge to the manifold. A one-way check valve at the outlet port to prevents back flow. In an alternative construction, a slotted or split stem, check valve provides noise free operation. The system finds particular advantage with cartridge based appliance systems, such as ice makers and chilled water dispensers at a refrigerator or water cooler, and for under cabinet cartridge mountings, such as at sinks.